Characteristics of Latex-Modified Bitumen Prepared via Foaming Technique Using Water and Diluted Methanol

Abstract

The ability of latex to notably improve the performance of asphalt pavements has established the material as a favorable modifier in asphalt systems. However, the high viscosity of latex-modified asphalt (LMA) binders significantly increases the production temperature of asphalt mixtures. One effective way to resolve this problem is by employing foaming technology, which was investigated in this study. Diluted methanol was used as a foaming agent due to its lower boiling point and energy consumption compared with water. Asphalt binder of penetration grade 60/70 was utilized as the binding agent. Latex accounted for 6% of the total weight of the asphalt binder. In this study, 1% water and 3% diluted methanol were added as foaming agents. The basic and rheological properties of asphalt binders were examined via different tests, for example, softening point, decay curves, rotational viscosity, torsional recovery, and dynamic shear rheometer. The findings showed that the presence of latex contributed to higher softening point, viscosity, elastic property, and rutting resistance to improve the pavement durability. The foaming agents (water or diluted methanol) decreased the viscosity and improved the expansion ratio producing better workability and aggregate coating during mixture production.